A known electric storage battery for use in an automobile comprises a casing in the form of a box of electrically insulating material divided by internal partition walls into a plurality of compartments each containing a cell assembly of plates and separators, and a lid closing the box. Each cell assembly is connected through the bounding partition wall or walls to the or each adjacent cell assembly, and each end cell assembly is connected to a respective electrode post received in a complementary bush mounted in the lid. The bushes in turn are electrically connected to the two electrode posts respectively thereby constituting positive and negative terminals for the battery. Such electric storage batteries are disclosed in GB-A-1500290 and GB-A-1569410.
It has long been known that some electrical equipment as found in automobiles or the like can be damaged if connected to an electrical storage battery with incorrect polarity, that is with a supply load intended for connection to the positive terminal connected to the negative terminal and vice versa, and a number of proposals have been made in an attempt to prevent such misconnection of equipment to the terminals of a battery. One such proposal is disclosed in GB-A-1356459 which discloses an arrangement in which in an attempt to avoid misconnection the terminals of the battery are made of mutually different shapes, each to have connected thereto a connector of an appropriate individual shape. More specifically, in this known arrangement the connector for connection of the negative terminal is a generally planar metal body of generally rectangular shape as seen in plan. For connection the body is stood on edge and abutted against one side of an upstanding wall of the negative terminal, the body and the wall being apertured to receive a bolt to secure the body to the terminal. The connector for connection to the positive terminal is a generally planar metal body of generally cruciform shape, and for connection it is abutted against an upstanding wall of the positive terminal, the wall extending from a base having a recess to receive one short arm of the cruciform shape, the body being secured to the terminal by means of a bolt. Even with such an arrangement it is still possible for an unskilled person to make a wrong connection, or this can happen to even a skilled person when working in awkward conditions such as at night.